VDR and psoriasis: Another similar characteristic between patients with psoriasis and those with HZ is plasma vitamin D levels that are lower than the normal range.[31] Chao et al. reported a positive association of serum vitamin D levels with immunity against VZV and illustrated immunomodulatory effects provided by the binding of vitamin D receptors to neutrophils, T cells, and antigen-presenting cells.[32, 33] Although vitamin D is used as a guideline therapy in patients with psoriasis, its immune reactions that contribute to the development of subsequent HZ should be considered.